1. Field of the Invention
The invention is a combination flash/flooded boiler system steam iron providing ironing flexibility and multimodes of operation by taking advantage of two well-known and separate types of operating systems.
2. Description of the Prior Art
There are generally two well-known and separate systems of steam irons and these are the flooded boiler and the flash boiler and irons are usually one version or the other. The flooded boiler is not widely used in this country but is used abroad. It allows water to drip into a soleplate steam boiler at a rate greater than the rate at which steam is formed so fills or floods the boiler. Once the boiler is flooded, the steam rate varies with the temperature setting of the iron since more water can be boiled away as steam at high temperature settings than at low temperature settings. When operating flooded, the steam is formed in the boiler like a teakettle at the boiling temperature (212.degree.F at sea level) and is separated from the boiler water and directed first into the tank and then ducted out the soleplate. A typical flooded boiler steam iron is shown in U.S. Pat. No. 3,156,054 of a common assignment.
The flash boiler system flashes the water immediately into steam and has the advantage of providing very quick steam operation after starting with a cold iron. However, to accomplish rapid flash steaming it is necessary to have sufficient heat storage in the metallic components in which the steam is generated and delivered or the steam merely condenses. Thus, the steam is typically relatively dry and substantially above the water boiling temperature. This steam may not be as satisfactory as a wetter lower temperature or saturated steam for moistening some fabrics since it does not condense as readily on the fabric to assist in ironing. Also, its steam rate does not vary with the temperature setting since it is a function of the sizing of the metering apparatus. This flash system has been particularly successful commercially in this country.
A simple and inexpensive iron using advantages of both the flooded boiler and the flash boiler to provide selectively both wet or saturated steam when operating in a flooded mode and dry super-heated steam when operating in a flash mode is disclosed in U.S. Pat. No. 3,896,572, also of common assignment. While workable, because of using the same water valve to provide different rates of flow as shown in FIGS. 2b and 2c of the 3,896,572 patent, some sealing problems were encountered with the fill valve at the top of the tank downstream of the fill opening through which the iron is filled with water. Because of the need to seal the fill opening at two vertically different positions to obtain the two rates of flow of water through the metering valve as shown in FIGS. 2b and 2c while opening the liquid fill valve when the metering valve is closed as in FIG. 2a or trying to seal in two vertical positions, the 3,896,572 patent is difficult to manufacture.
Thus, both flash and flooded boiler irons separately are well known, A combination flash/flooded boiler iron is disclosed in the above 3,896,572 patent. The present invention is a modified combination of the 3,896,572 patent to overcome the sealing problems and retain the advantages and provide an additional feature such as a vertical steamer.